.modal {
  display: none; 
  position: fixed; 
  z-index: 1000; 
  left: 0; top: 0; 
  width: 100%; height: 100%; 
  overflow: auto; 
  background-color: rgba(0,0,0,0.5);
}

.modal-content {
  background-color: #fff;
  margin: 15% auto;
  padding: 20px;
  width: 80%;
  max-width: 500px;
}

.close {
  float: right;
  font-size: 28px;
  cursor: pointer;
}